The 2004 FASEB summer research conference on Lymphocytes and Antibodies will be held from June 19-24, 2004 at Vermont Academy, Saxtons River, Vermont. This will be an intensive meeting with a relatively small number of participants (<160) that will cover topics at the cutting edge of immunological research. This conference will cover areas in which major advances are underway that have direct implications for health and human disease. The structure of this meeting is one that fosters a highly interactive atmosphere, promoting maximal scientific exchange and discussion among the participants. Further, this conference aims to bring together immunologists from a diversity of backgrounds and locations. There are no competing conferences of a similar size and format for the months surrounding this conference. The program will include the following areas: 1. Evolution of the Immune System - Martin Flajnik (U.Maryland), Session Organizer 2. Innate Immune Defense - Lewis Lanier (UCSF), Session Organizer 3. TCR gamma delta T cells- Wendy Havran, Session Organizer 4. Terminal B Cell Differentiation - Randy Noelle (Dartmouth), Session Organizer 5. T Cell Development - Stephen Hedrick (UCSD), Session Organizer 6. DC--sentinels of the Immune System - Muriel Moser (Univ. of Brussels), Session Organizer 7. Fine Tuning the Immune Response - Jeffrey Bluestone (UCSF), Session Organizer 8. In Vivo T Cell Activation - Marc Jenkins (UMINN), Session Organizer 9. Cytokine Control of Immunity - Leo Lefrancois (UCHC), Session Organizer